AS Biology P1 MCQs Preparation Thread

[Soldier313]

disulfide...will be as a result of r group interactions...n i dont think that's possible in ONE dipeptide...what do u say?

hmm i don't know i still feel that the answer should be all 3 : hydrogen, disulfide and peptide :/

 

[Soldier313]

that only occurs once...in the formation of mRNA...cuz when the 2 strands rejoin...it isn't the free nucleotides involved...neither is there any formation of sugar phosphate backbone againn

jazakallah bro, thanx a lot for yr help please do pray for me and i'll do the same inshaAllah

 

[Amaryllis]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s07_qp_1.pdf q26 the answer is D in this year but in
http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_w07_qp_1.pdf q25 which is the same question repeated the answer is B
what is the correct answer please?im confused :S

 

[Peter Check]

Is a chloroplast grana bigger than a nucleoli??

 

[Jaf]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf q26 the answer is D in this year but in
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_1.pdf q25 which is the same question repeated the answer is B
what is the correct answer please?im confused :S

lol read the questions again. Even though the choices are the same, the diagram is the same, the question is different.

 

[Nibz]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf q26 the answer is D in this year but in
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_1.pdf q25 which is the same question repeated the answer is B
what is the correct answer please?im confused :S

They are two completely different questions. Come on!

 

[Amaryllis]

lol read the questions again. Even though the choices are the same, the diagram is the same, the question is different.

LOL my bad!! i didnt focus well

 

[Peter Check]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf q26 the answer is D in this year but in
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_1.pdf q25 which is the same question repeated the answer is B
what is the correct answer please?im confused :S

Read the question, just because the options are the same doesn't mean the question is(the two questions are actually the opposite of each other), tell me if you still didnt get it.

 

[Peter Check]

Why is C or D wrong???

 

[duh shiekhni]

Why is C or D wrong?View attachment 12736

focus on wt exactly happens during ventricular diastole. when V.D occurs it means blood is filling in ventricles, and when it is filling, the atrio ventricular valves are open which led the filling of blood. the C and D are correct to an extnt but first things first. atrial pressure comes aftrwards... just focus on ventricles

 

[rogue94]

What is the theoretical number of chemically different dipeptides that may be assembled from 12
different types of amino acids?
A 24 B 72 C 144 D 400

How to do it ?????????? help rogue94

the Answer is 12^2 = 144 (option C). Dipeptide means that there are 2 amino acids in the chain and there are 12 different types of amino acids available to be part of the dipeptide. Therefore, 2 becomes the power of 12, giving the answer 144. If 20 different amino acids were available for a dipeptide, then the answer would have been 400 (20^2).

 

[XPFMember]

Nibz AsSalamoAlaikum Wr wb!
ehemm chek out n11 # 1 Q:14 and Q:6 of J'03 kinda same questions but different answers...or am i mistaken?

 

[Amaryllis]

Read the question, just because the options are the same doesn't mean the question is(the two questions are actually the opposite of each other), tell me if you still didnt get it.

thanks i got it now i just didnt focus i thought they're the same question

 

[thu]

help needed here !!!! View attachment 12721View attachment 12722View attachment 12723

which paper is the 3rd pic from. is the ans A in the scheme?

 

[littlecloud11]

Is a chloroplast grana bigger than a nucleoli??

No.

 

[Nibz]

Nibz AsSalamoAlaikum Wr wb!
ehemm chek out n11 # 1 Q:14 and Q:6 of J'03 kinda same questions but different answers...or am i mistaken?

Ws!

No, both are a bit different.

When water enters a plant cell, its volume increases and the living part of the cell presses on the cell wall which causes a pressure to build up inside the cell. This has the tendency to stop more water entering the cell. So the last option, i.e "Plant cell walls restrict the entry of water.. .. ." is right.

In the may/june question, since there is no such option as 'restriction of water by cell walls', the water potential inside and outside the cell must have been the same for the above explanation to stand true.

 

[littlecloud11]

Why is C or D wrong???View attachment 12739

D is definitely wrong. Both the atrium contract and relax simultaneously and the pressure in both rises and falls be the same amount.
C- the question asks about ventricular diastole only, not with atrial systole. Atrial and ventricular diastole can occur at the same time so it is not essential that the pressure in the atrium has to be greater than the ventricle.

 

[thu]

w11_12 Q40. Why is it D?

 

[sagystu]

J11:12 no.10 !!!!

 

[raamish]

what is the purpose of phosphate group of phospholipids. And why it being polar doesnt allow polar substances to cross it??? help plzzz